[Association between urinary neutrophil gelatinase-associated lipocalin and acute kidney injury after cardiac surgery].
OBJECTIVE
To test the hypothesis that Neutrophil gelatinase-associated lipocalin (NGAL) is an early biomarker for acute kidney injury (AKI) in patients after cardiac surgery.


METHODS
33 cases undergoing cardiac surgery were divided into AKI group and Non-AKI group according to the AKI criteria. The concentration of urine NGAL at different time points were measured.


RESULTS
(1) Nine of 33 cases (27%) developed postoperative AKI, but diagnosis with serum creatinine was only 12-48 hours after cardiac surgery. (2)Urinary concentrations of NGAL at 2 h after cardiac surgery in patients who did not developed AKI were significantly higher compared with those of preoperative (P < 0.001). Urinary concentrations of NGAL at 2 h and 4 h after cardiac surgery in patients who developed AKI were significantly higher compared with those of preoperative (P < 0.001). (3) The mean urinary NGAL concentrations in patients who developed AKI were significantly higher after surgery compared with patients who did not develop AKI (P < 0.01). (4) Urinary concentrations of NGAL/Ucr at 2 h and 4 h after cardiac surgery in patients who did not developed AKI were significantly higher compared with those of preoperative (P < 0.05). Urinary concentrations of NGAL/Ucr at 2 h and 4 h after cardiac surgery in patients who developed AKI were significantly higher compared with those of preoperative (P < 0.01). (The mean urinary concentrations of NGAL/Ucr in patients who developed AKI were significantly higher after surgery compared with patients who did not develop AKI (P < 0.01). (6) For concentrations in urine of NGAL at 2 h after surgery, sensitivity was 0.7125, and specificity was 0.7307 for a cutoff value of 250 microg/L. For concentrations in urine of NGAL/Ucr at 2 h after surgery, sensitivity was 0.8127, and specificity was 0.7839 for a cutoff value of 250 microg/mmol. (7) Urinary concentrations of NGAL at 2 h after cardiac surgery was significantly associated with serum creatinine 12 h postoperative (R = 0.638, P < 0.05).


CONCLUSIONS
The incidence of AKI in patients after cardiac surgery is high, which accounted for 27%. The amount of NGAL and NGAL/Ucr in urine at 2 h after cardiac surgery were the powerful independent predictor of acute renal injury and urine concentrations of NGAL/Ucr is more sensitive.
Wan
Xin
X
Department of Nephrology Nanjing First Hospital Affiliated to Nanjing Medical University, Nanjing, China.
Cao
Chang-chun
CC
Chen
Yu
Y
Xiao
Yu-long
YL
Wu
Wen-fang
WF
Chen
Xin
X
Mu
Xin-wei
XW
D058186:Acute Kidney Injury / Q000175:diagnosis / Q000209:etiology / Q000652:urine*; D000209:Acute-Phase Proteins / Q000652:urine*; D000328:Adult; D015415:Biomarkers / Q000652:urine; D002315:Cardiopulmonary Bypass / Q000009:adverse effects; D003404:Creatinine / Q000652:urine; D005260:Female; D006801:Humans; D000071068:Lipocalin-2; D054834:Lipocalins / Q000652:urine*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000175:diagnosis / Q000209:etiology / Q000652:urine; D011237:Predictive Value of Tests; D011518:Proto-Oncogene Proteins / Q000652:urine*; D055815:Young Adult
D000209:Acute-Phase Proteins; D015415:Biomarkers; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D011518:Proto-Oncogene Proteins; D003404:Creatinine